1. Field of the Invention
The present invention relates to a method of manufacturing an electric double layer capacitor with an improved step of superposing an insulating gasket with a separator.
2. Description of the Prior Art
Japanese Patent Laying-Open Gazettes Nos. 4227/1981 and 40916/1982 disclose examples of methods of manufacturing electric double layer capacitors. As shown in FIGS. 8 and 9, a conventional electric double layer capacitor 1 comprises an ion-permeable insulating separator 2 interposed between a pair of polarizable electrodes 4 and 6. Gaskets 8 and 10 of insulating rubber are provided around the peripheries of the polarizable electrodes 4 and 6. The polarizable electrodes 4 and 6 are formed by, e.g., activated carbon being hardened by a binder and being impregnated with an electrolyte. Numerals 12 and 14 indicate collecting electrodes, which are fixed to the outer surfaces of the gaskets 8 and 10.
In order to simultaneously obtain a number of such electric double layer capacitors 1, the prior art has generally employed a relatively large-sized gasket sheet made of the material for the gaskets 8 and 10. This gasket sheet is appropriately formed with through-holes serving as through-holes 8a and 8b of the gaskets 8 and 10, so that the separators 2 previously cut in circular configurations can be picked up one by one by forceps or the like and located on the gasket sheet to cover the said through-holes through a manual operation. In this case, adhesive is previously applied to either surface regions of the gasket sheet around the through-holes, or outer surfaces of the separators 2, so that the separators 2 are adhered to the regions around the through-holes of the gasket sheet upon location of the separators 2. Thereafter the polarizable electrodes 4 or 6 are inserted in the through-holes and the gasket sheet is cut in the units of respective electric double layer capacitors, each of which is assembled as shown in FIG. 8, to obtain the electric double layer capacitor 1 as shown in FIG. 9.
As hereinabove described, complicated manual operation has generally been required to adhere the separator 2 to the gasket 8 or 10. Further, the surface of the separator 2 may be damaged by the forceps or the like, leading to defects such as imperfect insulation.